Explain cellular injury [mechanisms, unintentional/unintentional, Infectious, Immunologic/Inflammatory Injury]. Flashcards
What is the main cause of hypoxia, the most common form of cellular injury?
A) Excessive production of reactive oxygen species (ROS)
B) Loss of hemoglobin
C) Decreased oxygen in the air
D) Increased production of red blood cells
Answer: C) Decreased oxygen in the air
Rationale: Hypoxia is primarily caused by a reduced amount of oxygen in the air, leading to inadequate oxygen supply to cells.
Which cellular response occurs when ATP levels decrease due to hypoxic injury?
A) Cellular swelling
B) Activation of autophagy
C) Detachment of ribosomes
D) Increased protein synthesis
Answer: A) Cellular swelling
Rationale: Decreased ATP levels in hypoxic injury result in cellular swelling due to sodium and water influx.
What is the main consequence of oxidative stress caused by free radicals?
A) Increased DNA synthesis
B) Protein misfolding and fragmentation
C) Enhanced membrane stability
D) Improved cell signaling
Answer: B) Protein misfolding and fragmentation
Rationale: Oxidative stress, induced by free radicals, can lead to protein misfolding and fragmentation, which can disrupt normal cellular function.
Which organelle is particularly vulnerable to damage by reactive oxygen species (ROS) during cellular injury?
A) Nucleus
B) Golgi apparatus
C) Mitochondria
D) Endoplasmic reticulum
Answer: C) Mitochondria
Rationale: Mitochondria are especially susceptible to damage by ROS, leading to mitochondrial dysfunction and cellular injury.
What is the main consequence of ischemia-reperfusion injury?
A) Activation of immune responses
B) Decreased calcium influx
C) Improved mitochondrial function
D) Enhanced cell survival
Answer: A) Activation of immune responses
Rationale: Ischemia-reperfusion injury leads to the activation of immune responses, including inflammation, due to the release of danger signals when cells die during reperfusion.
What mechanism primarily contributes to the inactivation or termination of free radicals?
A) Conversion of chemicals to free radicals
B) Formation of oxygen-derived metabolites
C) Spontaneous decay of free radicals
D) Activation of antioxidant systems
Answer: D) Activation of antioxidant systems
Rationale: The body can inactivate or terminate free radicals through the activation of antioxidant systems that neutralize these reactive species.
Which of the following is a consequence of mitochondrial permeability transition pore opening during mitochondrial damage?
A) Increased oxidative phosphorylation
B) Enhanced ATP production
C) Cellular necrosis
D) Improved mitochondrial DNA stability
Answer: C) Cellular necrosis
Rationale: Opening of the mitochondrial permeability transition pore leads to cellular necrosis due to mitochondrial dysfunction.
What happens when mitochondria store several proteins between their membranes and experience increased permeability of the outer membrane?
A) Enhanced ATP production
B) Improved protein synthesis
C) Leakage of proapoptotic proteins
D) Activation of autophagy
Answer: C) Leakage of proapoptotic proteins
Rationale: Increased permeability of the outer mitochondrial membrane can result in the leakage of proapoptotic proteins, leading to cellular death by apoptosis.
Question 1:
Which of the following is not a category of asphyxial injuries?
a) Suffocation
b) Strangulation
c) Electrocution
d) Drowning
Answer:
c) Electrocution
Rationale:
Asphyxial injuries comprise four general categories: suffocation, strangulation, chemical asphyxiants, and drowning. Electrocution, while related to injury and death, is not classified as an asphyxial injury.
Question 2:
What is the major mechanism of injury in drowning?
a) Blockage of the airways
b) Absorption of fluid by lungs
c) Elevated blood electrolyte levels
d) Laryngospasms
Answer:
b) Absorption of fluid by lungs
Rationale:
The major mechanism of injury in drowning is alteration of oxygen delivery to tissues resulting from the inhalation of fluid, usually water. The absorption of fluid by the lungs and subsequent disruption of oxygen delivery is the primary concern in drowning.
Question 3:
What distinguishes hanging strangulation from ligature strangulation in terms of neck marks?
a) Hanging leaves a horizontal mark, while ligature leaves an inverted V pattern.
b) Hanging leaves an inverted V pattern, while ligature leaves a horizontal mark.
c) Both hanging and ligature leave a horizontal mark.
d) Both hanging and ligature leave an inverted V pattern.
Answer:
b) Hanging leaves an inverted V pattern, while ligature leaves a horizontal mark.
Rationale:
In hanging strangulations, the mark on the neck usually has an inverted V pattern with the base of the V pointing toward the point of suspension. In ligature strangulation, the mark on the neck is horizontal without the inverted V pattern.
Question 4:
Which chemical acts as an asphyxiant by blocking the intracellular use of oxygen?
a) Carbon monoxide
b) Cyanide
c) Hydrogen sulfide
d) Oxygen
Answer:
b) Cyanide
Rationale:
Cyanide acts as an asphyxiant by combining with the ferric iron atom in cytochrome oxidase, thereby blocking the intracellular use of oxygen.
Question 5:
In drowning, what factor affects the progression from cerebral hypoxia to death?
a) Temperature of the water
b) Volume of water inhaled
c) Blood electrolyte levels
d) Length of submersion
Answer:
a) Temperature of the water
Rationale:
Irreversible injury in drowning develops much more rapidly in warm water than in cold water. The temperature of the water affects how quickly cerebral hypoxia progresses to death.
What is the key distinction between hypoxia and anoxia in asphyxial injuries?
a) Hypoxia is the complete deprivation of oxygen, while anoxia is partial oxygen deprivation.
b) Hypoxia is a total lack of oxygen, while anoxia is a lack of oxygen in the environment.
c) Hypoxia and anoxia are terms used interchangeably to describe asphyxial injuries.
d) Hypoxia refers to lack of oxygen due to chemical asphyxiants, while anoxia refers to lack of oxygen due to suffocation.
Answer: b) Hypoxia is a total lack of oxygen, while anoxia is a lack of oxygen in the environment.
Rationale: Hypoxia is the term used to describe partial oxygen deprivation, whereas anoxia refers to complete oxygen deprivation. It’s important to distinguish between these two terms when discussing asphyxial injuries.
What are the four general categories of asphyxial injuries described in the text?
a) Hypoxia, anoxia, strangulation, chemical suffocation
b) Suffocation, strangulation, electrocution, drowning
c) Suffocation, strangulation, chemical asphyxiants, drowning
d) Hypoxia, anoxia, poisoning, dehydration
Answer: c) Suffocation, strangulation, chemical asphyxiants, drowning
Rationale: The text mentions that asphyxial injuries comprise four general categories: suffocation, strangulation, chemical asphyxiants, and drowning
What is the immediate danger level when the ambient oxygen level drops to 16%?
a) Mild discomfort
b) Cerebral hypoxia
c) Death within minutes
d) No immediate danger
Answer: c) Death within minutes
Rationale: The text states that when the ambient oxygen level drops to 16%, it is immediately dangerous, and if the level is below 5%, death can occur within a matter of minutes.
What is the primary mechanism of injury in cases of strangulation?
a) Lack of airflow to the lungs
b) Compression and closure of blood vessels and air passages
c) Crushing of the trachea
d) Swelling of the soft tissues of the airway
Answer: b) Compression and closure of blood vessels and air passages
Rationale: Strangulation primarily involves the compression and closure of blood vessels and air passages due to external pressure on the neck, leading to cerebral hypoxia or anoxia.
What is the key distinction between ligature strangulation and hanging strangulation?
a) Ligature strangulation involves complete suspension of the body, while hanging strangulation does not.
b) Ligature strangulation results in an inverted V mark on the neck, while hanging strangulation results in a horizontal mark.
c) Ligature strangulation is less likely to cause internal neck injuries compared to hanging strangulation.
d) Ligature strangulation is caused by external pressure, while hanging strangulation is due to compression of the chest.
Answer: b) Ligature strangulation results in an inverted V mark on the neck, while hanging strangulation results in a horizontal mark.
Rationale: The text mentions that ligature strangulation typically results in a distinct mark on the neck with an inverted V pattern, whereas hanging strangulation has a different mark.
Which chemical asphyxiant combines with the ferric iron atom in cytochrome oxidase, blocking intracellular use of oxygen?
a) Carbon monoxide
b) Cyanide
c) Hydrogen sulphide
d) Oxygen
Answer: b) Cyanide
Rationale: Cyanide acts as a chemical asphyxiant by combining with the ferric iron atom in cytochrome oxidase, thereby blocking the intracellular use of oxygen.
What is the primary mechanism of injury in cases of drowning?
a) Hemolysis
b) Electrolyte disturbances
c) Hypoxemia
d) Fluid overload
Answer: c) Hypoxemia
Rationale: The text explains that the major mechanism of injury in drowning is hypoxemia, which is low blood oxygen levels resulting from the inhalation of fluid.
What is the term used to describe the phenomenon where little or no water enters the lungs in some drowning cases due to laryngospasms?
a) Dry-lung drowning
b) Freshwater drowning
c) Saltwater drowning
d) Asphyxial drowning
Answer: a) Dry-lung drowning
Rationale: Dry-lung drowning is the term used to describe the phenomenon where little or no water enters the lungs due to laryngospasms.
Which factor significantly influences the rate of irreversible injury in drowning cases?
a) Age of the individual
b) Health of the individual
c) Amount of inhaled water
d) Temperature of the water
Answer: d) Temperature of the water
Rationale: The text indicates that the temperature of the water significantly influences the rate of irreversible injury in drowning cases, with irreversible injury developing more rapidly in warm water than in cold water.
What are the three key factors determining the disease-producing potential of a microorganism mentioned in the text?
a) Invasion, histamine production, hypersensitivity reactions
b) Invasion, destruction of cells, production of toxins
c) Oxygen delivery, histamine production, cell proliferation
d) Genetic factors, epigenetic factors, nutritional imbalances
Answer: b) Invasion, destruction of cells, production of toxins
Rationale: The text states that the disease-producing potential of a microorganism depends on its ability to invade and destroy cells, produce toxins, and produce damaging hypersensitivity reactions.
How does complement contribute to membrane alterations during immunological injury?
a) By inducing laryngospasms
b) By binding with antibodies to enhance immune response
c) By causing rapid leakage of K+ out of the cell
d) By blocking receptor molecules on the plasma membrane
Answer: d) By blocking receptor molecules on the plasma membrane
Rationale: Complement is responsible for many of the membrane alterations that occur during immunological injury by blocking receptor molecules on the plasma membrane, interfering with cellular function.
